Wiring substrate with customization layers

Abstract

One or more customization layers can be added to a wiring substrate. The customization layers can provide customized electrical connections from electrical contacts of the base wiring substrate to electrical contacts at an outer surface of the customization layers, which can allow the contacts at the outer surface of the customization layers can be in a different pattern than the contacts at the surface of the base wiring substrate. The customization layers can comprise electrically insulating material, electrically conductive via structures through the insulating material, electrically conductive traces, electrically conductive jumpers electrically connecting two traces without contacting a trace disposed between the two traces, and/or other such elements. A jumper can be formed by making a relatively small deposit of electrically insulating material between the two traces to be connected and then making a relatively small deposit of electrically conductive material on parts of the two traces and the insulating material. Via structures can be coupled to traces and an insulating material can be cast around the via structures. Alternatively, via structures can be formed in openings with sloped side walls in an insulating layer.

We claim: 
     
       1. A multi-layer wiring substrate comprising:
 a base substrate; 
 a first layer of electrically conductive traces disposed on a surface of the base substrate; 
 a first rigid layer of electrically insulating material disposed on the first layer of traces and coupled to the surface of the base substrate; and 
 electrically conductive first vias embedded in the first layer of insulating material, each of the first vias comprising a stack of wire studs or a wire bonded to one of the traces of the first layer of traces and extending to an outer surface of the first layer of insulating material, 
 wherein the first layer of insulating material is cast around each said stack of wire studs or each said wire of the first vias, embedding each said stack of wire studs or each said wire of the first vias in the first layer of insulating material. 
 
     
     
       2. The multi-layer wiring substrate of  claim 1 , wherein the first layer of insulating material comprises a cured epoxy. 
     
     
       3. The multi-layer wiring substrate of  claim 1 , wherein the first vias comprise wires bonded to one of the traces of the first layer of traces. 
     
     
       4. The multi-layer wiring substrate of  claim 3 , wherein a body of each of the wires extends from one of the traces of the first layer of traces substantially vertically with respect to the surface of the base substrate. 
     
     
       5. The multi-layer wiring substrate of  claim 3 , wherein a body of each of the wires extends from one of the traces of the first layer of traces at an angle between fifteen and seventy-five degrees with respect to the surface of the base substrate. 
     
     
       6. The multi-layer wiring substrate of  claim 5  further comprising a second layer of electrically conductive traces on the outer surface of the first layer of insulating material, wherein each of the traces of the second layer of traces is electrically connected to one of the first vias. 
     
     
       7. The multi-layer wiring substrate of  claim 6  further comprising:
 a second layer of electrically insulating material disposed on the second layer of traces and the outer surface of the first layer of insulating material; and 
 electrically conductive second vias embedded in the second layer of insulating material, each of the second vias comprising a stack of wire studs or a wire bonded to one of the traces of the second layer of traces and extending to an outer surface of the second layer of insulating material, 
 wherein second layer of insulating material is cast around each said stack of wire studs or each said wire of the second vias, embedding each said stack of wire studs or each said wire of the second vias in the second layer of insulating material. 
 
     
     
       8. The multi-layer wiring substrate of  claim 7  further comprising a third layer of electrically conductive traces on an outer surface of the second layer of insulating material, the traces of the third layer of traces electrically connected to the second vias. 
     
     
       9. The multi-layer wiring substrate  1 , wherein each of the first vias consists only of one said stack of wire studs or one said wire. 
     
     
       10. The multi-layer wiring substrate of  claim 1 , wherein the first vias each comprise a stack of wire studs bonded to one of the traces of the first layer of traces. 
     
     
       11. The multi-layer wiring substrate of  claim 10 , wherein each said stack of wire studs comprises at least three wire studs stacked one on top of the other. 
     
     
       12. The multi-layer wiring substrate of  claim 1 , wherein the first layer of insulating material is a hardened material that was cast in a viscous state around each said stack of wire studs or each said wire of the first vias. 
     
     
       13. The multi-layer wiring substrate of  claim 1 , wherein the first layer of insulating material comprises silica particles. 
     
     
       14. The multi-layer wiring substrate of  claim 13 , wherein a concentration of the silica particles in the first layer of insulating material is fifty to ninety percent by weight.